Occurs when the origin web server refuses connections from Cloudflare. Security solutions at your origin may block legitimate connections from certain Cloudflare IP addresses. The most common ones are:

  • Offline origin web server application
  • Blocked Cloudflare requests


Step 1: Contact NET Support

Contact your site administrator or NET Support to eliminate these common causes:

  • Ensure your origin web server is responsive
  • Review origin web server error logs to identify web server application crashes or outages.
  • Confirm Cloudflare IP addresses are not blocked or rate limited
  • Whitelist all Cloudflare IP ranges in your origin web server’s firewall or other security software
  • Find additional troubleshooting information on the Cloudflare Community.